Fig. 5.

STAT3 is an essential factor in MAP2K3‐mediated tumorigenesis in ESCC. (A) The transfection efficiency of indicated plasmids was detected by western blot. (B) Cell growth was detected by CCK8 in KYSE150 and KYSE520 cells with indicated transfection. (C) Colony formation was detected in STAT3 and MAP2K3 transfected KYSE150 and KYSE520 cells. (D) Cell invasion was detected in STAT3 and MAP2K3 transfection cells by Transwell assay. (E) Western blot was performed to detect the expression of (cl‐) PARP and caspase 9 in KYSE150 cells after indicated transfection. (F) MAP2K3 and STAT3 expression was evaluated by IHC (n = 140, scale bars: 200 µm). The IHC score and the correlation between STAT3 and MAP2K3 expression in ESCC patients were shown. (G). The 5‐week‐old immunodeficient nude mice (4 mice per group) were injected subcutaneously with indicated cells (1 × 10⁷ cells). (H). Tumor volume and weight were measured at day 30. (I) Immunohistochemistry analysis of STAT3 and Ki67 of tumor xenografts with indicated treatment (scale bar: 200µm, 50 µm, respectively). Error bars represent the SD from at least three independent biological replicates (*P < 0.05; **P < 0.01; ***P < 0.001 by Student’s t‐test).